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are dissolved by a carbo-chloration technique. After dissolution, U can be electrodeposited as a<br />

metal on a solid cathode, then the TRUs can be recovered by electrolysis using a liquid<br />

cadmium or bismuth cathode. CRIEPI is also studying the partitioning of MAs by liquid-liquid<br />

extraction using a LiCl+KCl salt bath and Cd or Bi metallic solvents containing Li as a<br />

reducing agent. In this case, liquid-liquid extraction corresponds to the reductive transfer of a<br />

metal from the salt bath, where it exists as M n+ cation, to the metal solvent, where M exists as a<br />

M 0 solute.<br />

The equation of the extraction reaction can be written as follows:<br />

n+<br />

0<br />

0<br />

+<br />

M + n Li ⇔ M + n Li<br />

(4)<br />

(salt)<br />

(Cd or Bi metal phase)<br />

(Cd or Bi metal phase)<br />

Large expertise has been gained by CRIEPI in this field but only with surrogates of actinides. A<br />

joint CRIEPI-ITU programme is under way to test the process with actinides.<br />

• JAERI<br />

JAERI is studying pyroprocessing for the possible treatment of nitride, oxide or metallic spent<br />

fuels in order to prepare nitride fuels enriched with 15 N for FRs. After dissolution of the spent<br />

fuels into a LiCl+KCl eutectic salt bath, the actinides will be electrodeposited on solid or liquid<br />

(Cd) cathodes. The recovered actinide metals will then be converted into actinides nitrides after<br />

their dissolution in liquid cadmium. The nitruration agent will be N2 or Li3N.<br />

• JNC<br />

JNC is also engaged in the development of pyro processes aiming to reprocess FR spent fuels.<br />

The method selected are similar to those studied by CRIEPI: (i) choice of LiCl+KCl eutectic bath,<br />

(ii) electrodeposition method, (iii) liquid-liquid extraction between salt bath and liquid Cd metal.<br />

2.3.2.4 France<br />

Two years ago, the CEA has launched a programme dedicated to the partitioning of MAs by “pyro”<br />

processing. A research team was created at CEA/Marcoule and special hot facilities have been created. The<br />

programme selected is rather wide. It will consider both chloride and fluoride melts and the most important<br />

separation techniques known to be effective in “pyroprocessing”, i.e. (i) electrodeposition, (ii) oxide<br />

precipitation, (iii) liquid-liquid extraction between fused salt bath and a metallic solvent. The results<br />

obtained to-date concern mainly the basic understanding of the chemistry of actinides (U, Pu and Am) in<br />

solution in the fused melts. Process developments are also underway and active tests on irradiated objects<br />

are foreseen to be done before 2005.<br />

2.3.2.5 Czech Republic<br />

At Rez Institute, Czech scientists are developing a process based on the dual use of actinide<br />

hexafluoride volatilisation and pyroprocessing of the wastes from a fluoride melt. This research<br />

programme is connected with the interest of Czech Republic for the development of the molten salt<br />

reactor (MSR) technology. Facilities are under construction at Rez Institute for testing the pyroprocesses.<br />

(salt)<br />

62

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